1. Field Of the Invention
This invention relates to a method and apparatus for transporting materials, such as longwall mining shields and other equipment and material, in an underground mine, and more particularly, to a self-propelled vehicle maneuverable in an underground mine to unload and load equipment and materials onto a solid deck for transporting to a desired location in the mine.
2. Description of the Prior Art
Self-propelled vehicles for moving equipment and materials into and out of an underground mine are well known in the art, as disclosed in U.S. Pat. Nos. 4,199,299; 4,411,583; 4,799,850; 4,995,783; and 5,076,749. With each of these devices a self-propelled vehicle transports the mine material and equipment into and out of the mine. Preferably, the vehicle is propelled by a pair of endless tracks. The vehicle is maneuverable to safely and efficiently transport equipment or materials into and out of the mine and to any desired location in the mine up to the mine face.
The traction vehicle is equipped with a selected materials handling and transporting device. The track propelled vehicle is particularly adapted in the assembly and disassembly of of longwall mining systems that include various components such as shields, pans, cribbing, roof supports, conveyors, and the like.
The machines disclosed in U.S. Pat. Nos. 4,199,299 and 4,799,850 feature a boom assembly that extends from the body of a track propelled vehicle maneuverable in an underground mine. A pivot arrangement supports the boom assembly for lateral movement from the rear end of the vehicle. One or more piston assemblies are used to raise and lower the boom assembly and swing the boom assembly horizontally. Housed within the boom assembly is a single piston cylinder connected to telescoping sections which allow for longitudinal extension and retraction of the assembly from the free end of the vehicle for movement of a material engaging device.
With the above-described vehicle, the preferred material engaging device connected to the free end of the boom assembly is a hook member rotatably positioned within a socket connected to the end of the boom assembly. The hook member is operable to assist in performing a number of lifting and moving operations, such as moving the components of a longwall mine system into and out of position at the mine face. The mining machine component is connected to the hook member by a chain at the end of the telescoping boom. As the vehicle is trammed, the mining machine component is towed behind the vehicle. The machine component is not loaded onto the vehicle for hauling.
The above-described self-propelled mine vehicle is modifiable from operations of moving longwall mining machine components to conducting materials handling operations, such as bulldozing, grading, transporting, and unloading operations. This is accomplished by removing the hook member from the telescoping boom and attaching a multi-purpose bucket as disclosed in U.S. Pat. No. 4,411,583. The multi-purpose bucket is connected to the end of the boom assembly for pivotal, lateral, and vertical movement relative to the vehicle frame.
The conversion from a hook member to a multi-purpose bucket on the end of the boom is readily accomplished through a quick release pin connection. The multi-purpose bucket extends rearwardly from the machine frame and is movable relative thereto by operation of the telescoping boom. The telescoping operation of the boom is performed by a single piston cylinder assembly housed within the boom.
The above-identified material handling mine vehicles perform material handling and transporting operations removed from the vehicle. The telescoping boom member engages the equipment or material, depending upon the type of attachment connected to the boom member, positioned on the ground behind the vehicle. The equipment is towed from behind the vehicle to the desired location in the mine. The equipment or material is not loaded onto the mobile frame.
U.S. Pat. Nos. 4,995,783 and 5,076,749 disclose a material transport vehicle having a material handling platform for carrying equipment and material on the vehicle, as opposed to towing the equipment positioned on the ground behind the vehicle. The material handling platform is pivotally attached to the front of the transport vehicle for vertically raising and lowering the platform, as well as tilting the platform horizontally forwardly and backwardly. A turntable is mounted on platform.
To position a piece of equipment on the material handling platform, a winch cable is extended from the vehicle over the handling platform and attached to the equipment to be carried on the platform. The platform is lowered on the ground and tilted to form an inclined surface for pulling the equipment, such as a mine roof support, from the ground onto the surface of the platform.
Once the equipment is loaded onto the platform, the platform is tilted to a horizontal position and raised out of contact with the ground. The vehicle is trammed to move the equipment to the desired location in the mine. At the desired location, the turntable is rotated so that the equipment is in the desired position when it is unloaded from the vehicle. Unloading is accomplished by lowering and tilting the platform in contact with the ground. The equipment is then slid from the material handling platform onto the ground.
The material handling platform disclosed in U.S. Pat. No. 4,995,783 extends forwardly from the vehicle frame. It is connected at one end to the vehicle frame for vertical movement relative to the ground as well as a tilted position relative to the ground. The material handling platform opposite the machine frame is unsupported. There is no provision for retracting the material handling platform with the load positioned thereon onto the body of the vehicle. The platform must be securely connected to the vehicle frame to support the equipment when the platform is elevated during tramming. The equipment extends forwardly from the vehicle and is not supported by the body of the vehicle. Consequently, the ability of the vehicle to transport equipment into and out of the mine is limited by the capacity of the handling platform that extends forwardly of the vehicle.
While the above-described material transport vehicles are suitable for carrying out a number of material handling operations in an underground mine, including the transportation of longwall mining components into the mine and maneuvering the components into position adjacent to the mine face, the current vehicles are limited in their capacity to transport mine equipment. There is a need for a materials transport vehicle capable of moving equipment weighing over 30-tons. Transport vehicles having a material handling platform extending forwardly of the vehicle cannot accommodate equipment of this size. Also, to tow a 30-ton longwall shield attached to a telescoping boom extending from a transport vehicle through the mine and into position adjacent to the mine face presents substantial difficulties and hazards to the equipment and operating personnel. This is particularly evident in towing and moving into position large shields when attached to the end of a telescopic boom. The boom is in an extended position when towing the shield through the mine. Once the shield has been moved to the desired location, it must be maneuvered into position by pivotal movement of the boom in either an extended or retracted position.
The load capacity of a conventional materials handling boom is limited to the single piston cylinder assembly encased in the boom. At the very most, the piston cylinder assembly is a multi-stage jack in which multiple cylinders extend one from another. With both arrangements, the entire load is applied to a single cylinder. The single cylinder must withstand substantial tortional forces tending to twist and bend the boom when pulling and pushing against the load. While it has been suggested, as disclosed in U.S. Pat. No. 4,252,475, to reinforce hydraulic cylinders by guide plates to resist buckling moments, a single piston cylinder assembly is utilized to control the range of movement of the load.
Therefore, there is need for a multi-purpose, self-propelled materials handling device maneuverable in an underground mine to safely and efficiently transport large components, such as longwall shields, a substantial distance through the mine. The mining equipment and material should be carried on the body of the vehicle rather than towed on the ground from the rear of the vehicle or supported in a suspended position at the front of the vehicle. In this manner the demands for moving large pieces of equipment throughout the mine can be safely and efficiently carried out.
In accordance with the present invention there is provided a materials transport vehicle for use in an underground mine that includes a mobile frame and a boom assembly extending longitudinally on the mobile frame. The boom assembly includes a boom housing having a first end portion and a second end portion. An extension mechanism is supported by the boom housing for movement between an extended position and a retracted position to extend and retract the boom member assembly. The extension mechanism has a first end portion connected to the mobile frame and a second end portion extending on the mobile frame forwardly from the first end portion. The extension mechanism includes a pair of piston cylinders positioned in overlying relation in said boom housing. A first piston cylinder has a fixed end portion pivotally connected to the mobile frame and an extensible end connected to the boom housing. A second piston cylinder underlies the first piston cylinder. The second piston cylinder has a fixed end connected to the boom housing and an extensible end extendable from the boom housing on the mobile frame. The extension mechanism is operable upon actuation to extend the first piston cylinder to extend the boom housing on the mobile frame and extend the second piston cylinder to extend the extendable end thereof from the boom housing to move the boom assembly from a retracted position to an extended position on the mobile frame.
Further in accordance with the present invention there is provided a method for extending and retracting a boom assembly on a materials transport vehicle that includes the steps of positioning a boom housing longitudinally on a mobile frame. The boom housing is connected to the mobile frame by a first piston cylinder assembly positioned in the boom housing. A second piston cylinder assembly is connected to the boom housing in underlying relation with the first piston cylinder assembly. The first piston cylinder assembly is actuated to advance the boom housing to an extended position on the mobile frame. The second piston cylinder assembly is actuated to extend an end portion thereof from the extended boom housing.
Further the present invention is directed to a mining equipment transporting apparatus that includes a mobile body portion having a longitudinally extending frame. A pair of ground traction devices are positioned laterally opposite one another on the mobile frame. A solid deck is positioned on the mobile frame for loading, transporting, and unloading mine materials and equipment on the body portion. The deck extends longitudinally and laterally between the ground traction devices. The deck has an operator end portion and an equipment receiving end portion. A boom assembly extends longitudinally on the solid deck. The boom assembly has a first end portion pivotally mounted on the deck operator end portion and a second end portion extending toward the deck equipment receiving end portion. Extensible means is provided for extending and retracting the boom assembly second end portion relative to the boom assembly first end portion. A material engaging device is connected to the boom assembly second end portion for engaging mine equipment to be loaded and unloaded on the deck for use in the mine. The boom assembly is movable between an extended position from the deck equipment receiving end portion to a retracted position on the deck adjacent to the deck operator end portion. The boom assembly is operable upon actuation with the material engaging device attached to the mining equipment to move from the extended position to the retracted position to load the mine equipment onto the deck between the pair of ground traction devices for transporting the mine equipment to a selected location in the mine. The boom assembly second end portion has an abutment surface for exerting a force upon the mine equipment on extension of the boom assembly from the retracted position to the extended position to move the mine equipment on the deck for unloading at the deck equipment receiving end portion.
Additionally, the present invention is directed to a materials transporting apparatus that includes a mobile body and a solid deck positioned on the mobile body for receiving and transporting materials. A boom member is pivotally mounted on the deck and has a free end portion extending above the deck. A hook mechanism is connected to the boom member free end portion for engaging material to be moved onto and off of the deck. The hook mechanism includes a socket assembly attached to the boom member free end portion. The socket assembly has a cavity for pivotally receiving a hook attached to the socket assembly. The hook is pivotally movable on the socket assembly between a retracted position in the cavity and an extended position from the cavity. The socket assembly has an abutment surface surrounding the cavity for applying a ramming force to displace material from the deck when the hook is in the retracted position on the socket assembly.
Accordingly, a principal object of the present invention is to provide method and apparatus for loading, transporting, and unloading equipment and materials on a self-propelled vehicle in an underground mine.
Another object of the present invention is to provide a self-propelled materials transport vehicle for use in an underground mine in which an extensible boom is positioned on a loading deck between propelling tracks of the vehicle to load onto the deck equipment which is then transported to a desired location in the mine and unloaded onto the mine floor by operation of the boom member.
A further object of the present invention is to provide a track-driven vehicle for transporting longwall shields and other components on the vehicle into and out of position adjacent a longwall mining machine in an underground mine.
Additionally, the present invention is directed to a self-propelled vehicle having a materials loading and unloading mechanism capable of receiving loose material on a haulage deck of the vehicle for transporting to a desired location where the equipment is unloaded for use.
A further object of the present invention is to provide a self-propelled materials transport device for use in an underground mine in which an extensible boom has a capacity to load and unload onto the deck of the vehicle large tonnage equipment for retrieval and installation at a desired location in an underground mine.
These and other objects of the present invention will be more completely disclosed and described in the following specification, the accompanying drawings, and the appended claims.